linux/fs/9p/v9fs.h
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   1/*
   2 * V9FS definitions.
   3 *
   4 *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
   5 *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   6 *
   7 *  This program is free software; you can redistribute it and/or modify
   8 *  it under the terms of the GNU General Public License version 2
   9 *  as published by the Free Software Foundation.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *  GNU General Public License for more details.
  15 *
  16 *  You should have received a copy of the GNU General Public License
  17 *  along with this program; if not, write to:
  18 *  Free Software Foundation
  19 *  51 Franklin Street, Fifth Floor
  20 *  Boston, MA  02111-1301  USA
  21 *
  22 */
  23#ifndef FS_9P_V9FS_H
  24#define FS_9P_V9FS_H
  25
  26#include <linux/backing-dev.h>
  27
  28/**
  29 * enum p9_session_flags - option flags for each 9P session
  30 * @V9FS_PROTO_2000U: whether or not to use 9P2000.u extensions
  31 * @V9FS_PROTO_2000L: whether or not to use 9P2000.l extensions
  32 * @V9FS_ACCESS_SINGLE: only the mounting user can access the hierarchy
  33 * @V9FS_ACCESS_USER: a new attach will be issued for every user (default)
  34 * @V9FS_ACCESS_CLIENT: Just like user, but access check is performed on client.
  35 * @V9FS_ACCESS_ANY: use a single attach for all users
  36 * @V9FS_ACCESS_MASK: bit mask of different ACCESS options
  37 * @V9FS_POSIX_ACL: POSIX ACLs are enforced
  38 *
  39 * Session flags reflect options selected by users at mount time
  40 */
  41#define V9FS_ACCESS_ANY (V9FS_ACCESS_SINGLE | \
  42                         V9FS_ACCESS_USER |   \
  43                         V9FS_ACCESS_CLIENT)
  44#define V9FS_ACCESS_MASK V9FS_ACCESS_ANY
  45#define V9FS_ACL_MASK V9FS_POSIX_ACL
  46
  47enum p9_session_flags {
  48        V9FS_PROTO_2000U        = 0x01,
  49        V9FS_PROTO_2000L        = 0x02,
  50        V9FS_ACCESS_SINGLE      = 0x04,
  51        V9FS_ACCESS_USER        = 0x08,
  52        V9FS_ACCESS_CLIENT      = 0x10,
  53        V9FS_POSIX_ACL          = 0x20
  54};
  55
  56/* possible values of ->cache */
  57/**
  58 * enum p9_cache_modes - user specified cache preferences
  59 * @CACHE_NONE: do not cache data, dentries, or directory contents (default)
  60 * @CACHE_LOOSE: cache data, dentries, and directory contents w/no consistency
  61 *
  62 * eventually support loose, tight, time, session, default always none
  63 */
  64
  65enum p9_cache_modes {
  66        CACHE_NONE,
  67        CACHE_LOOSE,
  68        CACHE_FSCACHE,
  69};
  70
  71/**
  72 * struct v9fs_session_info - per-instance session information
  73 * @flags: session options of type &p9_session_flags
  74 * @nodev: set to 1 to disable device mapping
  75 * @debug: debug level
  76 * @afid: authentication handle
  77 * @cache: cache mode of type &p9_cache_modes
  78 * @cachetag: the tag of the cache associated with this session
  79 * @fscache: session cookie associated with FS-Cache
  80 * @options: copy of options string given by user
  81 * @uname: string user name to mount hierarchy as
  82 * @aname: mount specifier for remote hierarchy
  83 * @maxdata: maximum data to be sent/recvd per protocol message
  84 * @dfltuid: default numeric userid to mount hierarchy as
  85 * @dfltgid: default numeric groupid to mount hierarchy as
  86 * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
  87 * @clnt: reference to 9P network client instantiated for this session
  88 * @slist: reference to list of registered 9p sessions
  89 *
  90 * This structure holds state for each session instance established during
  91 * a sys_mount() .
  92 *
  93 * Bugs: there seems to be a lot of state which could be condensed and/or
  94 * removed.
  95 */
  96
  97struct v9fs_session_info {
  98        /* options */
  99        unsigned char flags;
 100        unsigned char nodev;
 101        unsigned short debug;
 102        unsigned int afid;
 103        unsigned int cache;
 104#ifdef CONFIG_9P_FSCACHE
 105        char *cachetag;
 106        struct fscache_cookie *fscache;
 107#endif
 108
 109        char *uname;            /* user name to mount as */
 110        char *aname;            /* name of remote hierarchy being mounted */
 111        unsigned int maxdata;   /* max data for client interface */
 112        unsigned int dfltuid;   /* default uid/muid for legacy support */
 113        unsigned int dfltgid;   /* default gid for legacy support */
 114        u32 uid;                /* if ACCESS_SINGLE, the uid that has access */
 115        struct p9_client *clnt; /* 9p client */
 116        struct list_head slist; /* list of sessions registered with v9fs */
 117        struct backing_dev_info bdi;
 118        struct rw_semaphore rename_sem;
 119};
 120
 121/* cache_validity flags */
 122#define V9FS_INO_INVALID_ATTR 0x01
 123
 124struct v9fs_inode {
 125#ifdef CONFIG_9P_FSCACHE
 126        spinlock_t fscache_lock;
 127        struct fscache_cookie *fscache;
 128#endif
 129        struct p9_qid qid;
 130        unsigned int cache_validity;
 131        struct p9_fid *writeback_fid;
 132        struct mutex v_mutex;
 133        struct inode vfs_inode;
 134};
 135
 136static inline struct v9fs_inode *V9FS_I(const struct inode *inode)
 137{
 138        return container_of(inode, struct v9fs_inode, vfs_inode);
 139}
 140
 141struct p9_fid *v9fs_session_init(struct v9fs_session_info *, const char *,
 142                                                                        char *);
 143extern void v9fs_session_close(struct v9fs_session_info *v9ses);
 144extern void v9fs_session_cancel(struct v9fs_session_info *v9ses);
 145extern void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses);
 146extern struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 147                        unsigned int flags);
 148extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d);
 149extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
 150extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 151                        struct inode *new_dir, struct dentry *new_dentry);
 152extern void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd,
 153                        void *p);
 154extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
 155                                         struct p9_fid *fid,
 156                                         struct super_block *sb, int new);
 157extern const struct inode_operations v9fs_dir_inode_operations_dotl;
 158extern const struct inode_operations v9fs_file_inode_operations_dotl;
 159extern const struct inode_operations v9fs_symlink_inode_operations_dotl;
 160extern struct inode *v9fs_inode_from_fid_dotl(struct v9fs_session_info *v9ses,
 161                                              struct p9_fid *fid,
 162                                              struct super_block *sb, int new);
 163
 164/* other default globals */
 165#define V9FS_PORT       564
 166#define V9FS_DEFUSER    "nobody"
 167#define V9FS_DEFANAME   ""
 168#define V9FS_DEFUID     (-2)
 169#define V9FS_DEFGID     (-2)
 170
 171static inline struct v9fs_session_info *v9fs_inode2v9ses(struct inode *inode)
 172{
 173        return (inode->i_sb->s_fs_info);
 174}
 175
 176static inline struct v9fs_session_info *v9fs_dentry2v9ses(struct dentry *dentry)
 177{
 178        return dentry->d_sb->s_fs_info;
 179}
 180
 181static inline int v9fs_proto_dotu(struct v9fs_session_info *v9ses)
 182{
 183        return v9ses->flags & V9FS_PROTO_2000U;
 184}
 185
 186static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses)
 187{
 188        return v9ses->flags & V9FS_PROTO_2000L;
 189}
 190
 191/**
 192 * v9fs_get_inode_from_fid - Helper routine to populate an inode by
 193 * issuing a attribute request
 194 * @v9ses: session information
 195 * @fid: fid to issue attribute request for
 196 * @sb: superblock on which to create inode
 197 *
 198 */
 199static inline struct inode *
 200v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 201                        struct super_block *sb)
 202{
 203        if (v9fs_proto_dotl(v9ses))
 204                return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 0);
 205        else
 206                return v9fs_inode_from_fid(v9ses, fid, sb, 0);
 207}
 208
 209/**
 210 * v9fs_get_new_inode_from_fid - Helper routine to populate an inode by
 211 * issuing a attribute request
 212 * @v9ses: session information
 213 * @fid: fid to issue attribute request for
 214 * @sb: superblock on which to create inode
 215 *
 216 */
 217static inline struct inode *
 218v9fs_get_new_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 219                            struct super_block *sb)
 220{
 221        if (v9fs_proto_dotl(v9ses))
 222                return v9fs_inode_from_fid_dotl(v9ses, fid, sb, 1);
 223        else
 224                return v9fs_inode_from_fid(v9ses, fid, sb, 1);
 225}
 226
 227#endif
 228
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